The present invention relates to a power semiconductor module which is used for the power conversion and control.
A power conversion apparatus is equipped with a function of converting a DC power, which is supplied from a DC power-source, into an AC power. This AC power is then supplied to an AC electric load such as a rotating electric machine. Otherwise, the power conversion apparatus is equipped with a function of converting an AC power, which is generated by a generator, into a DC power. In order to accomplish the power conversion functions like these, the power conversion apparatus includes a power conversion circuit such as an inverter circuit. This power conversion circuit employs therein power semiconductor modules which are equipped with a current-switching function. Accordingly, by repeating the electric-conduction operation and the electric-interrupt operation, the power conversion apparatus performs the power conversion from the DC power to the AC power or from the AC power to the DC power.
Each power semiconductor module is fabricated as follows: Namely, an insulating board, on which a wiring pattern is formed, is bonded on a heatsink-use metallic base by using a method such as soldering. Moreover, a plurality of semiconductor elements are mounted on the wiring pattern on the insulating board in such a manner that the semiconductor elements establish an in-parallel connection to each other. On a large-power-use power semiconductor module, the plural number of insulating boards are mounted in order to perform the switching for the large current. This configuration allows implementation of the in-parallel connection of the large number of semiconductor elements.
As the conventional power semiconductor modules like these, there have been known the ones that are disclosed in JP-A-4138192, JP-A-4484400, JP-A-4142539, and JP-A-2002-141465.